Externally-expanded piston



June 17, 1930. A, MCLEAN 1,764,458

EXTERNALLY EXPANDED PISTON 'Filed April 1927 .2 SheetsSheet l- June 17, 1930. McLEAN EXTERNALLY EXPANDED PISTON Filed April 4, 1927 2 Sheets-Sheet. 2

Patented June 17, 193!) PATENT? arms ANDY McLEAN, or runnngron, casprroama nx'rnainnnx-nxrannnn rrsron Application filed April 1927. Serial ll'o. 180,842.

Thisinvention relates to oil well apparatus, and more particularly to a slush-pump for use in connection with rotary drilling outfits, and it is an object of this invention to provide a slush-pump which is designed to withstand the high pressure and heavy duty.

re uired for deep well drilling. second object of this invention is to provide a pump having an expansible piston 1 therein that will prevent'leakage within the of the piston in the slush-pump.

My invention is susceptible to modification, and it also contemplates another simple, practical and efiective combination wherein there is provided a grease-pump adapted to receive power from the slush-pump and force grease to the interior of the piston to equalize the pressure within the piston and without.

The essential feature of the invention involved in the carrying out of the objects indicated however, is the provision of a slushpump which has a piston therein, which piston is provided with means for equalizing the pressure within and without, or exceeding the pressure without by the pressure within, to prevent leakage and to provide a ump which is strong and durable, efiicient 1n its operation, is, unlikely to get out of order, and which is well adaptedto perform the services required of it. 4

The essential features of the invention involved in the carrying out of the objects indicated are susceptible to modification; but a preferred ,embodiment of the invention is shown in the accompanying drawings, in which:

Figure 1 is a-side elevation of the slushpump and the auxiliary connections associated therewith, showing certain operative parts broken away to reveal the operative parts thereof.

Figure 2 is a detailedsectional view of a portion of'the cross-head.

Figure 3 is a sectional view taken longitudinally through a portion of the slushpumpshowing the operative parts of the expansible piston.

Figures 4, 5 and 6 are views similar to Figures 1, 2 and 3 respectively, showing a slightly modified form of my invention.

Figure 7 is a sectional view taken along the lines 77 of Figure 6.

The device involves in its general organization a skid 1, upon which is mounted a base plate 2 which supports the slush-pump 3. The skid also has mounted thereon, a motor 4 and a grease gun 5 which will be described in detail later, and a main steam cylinder 6 havinga valve chamber 7 therein and suitable connections 8. This last mentioned cylinder, its valve chamber and its connections are merely conventional in form, and no claim is laid as to the novelty of the same. The invention lies in the other operative parts of the combination device. The slush-' pump 3 is provided with an outer casing 9 and a cylinder 10 therein. Extending through this casing as at 11, is a port adapted, to be closed by a suitable plug 12. 'A piston 13 is slidably disposed within the cylinder walls 10, which cylinder is shown in detail in Figure 3. A hollow piston rod (water end) is provided at 14, and a solid piston rod (steam end) is provided at 15. These piston rods are in alignment and are connected to a suitable cross-head assembly 16. The piston rod 14 is hollow byvirtue of a bore 17 extending therethrough to the interior of the piston, and an alemite connection 18 is formed on the cross-head and communicates with the interior of the bore 17. From the steam chamber of the steam-pump 6 a connec-- tion is formed, which connection leads to the steam end of the motor 4. This motor has a piston 19 therein and a suitable cup leather 20 is formed on one side of the piston. A connecting rod 21 leads through a stuflingbox 22 and is connected at its other end to a piston 23 within the grease gun-5. The pressure end of this grease gun is adapted to have a supply of grease inserted therein as at 24, 100

through the plug 25, and a flexible alemite hose 26 leads from the chamber wherein the grease is disposed through the port 27 to the alemite connection 18. A second port 28 is formed in the end plate of the grease gun 5,

by the steam chamber of the steam pump 6.

The piston 13, which constitutes an important part of this invention, is designated as an entirety at 13 in Figure 3, and comprises a body portion 30 having an annular recess 31 disposed centrally thereof, and in this annular recess there is adapted to be mounted a ring of flexible material 32, which ring may be formed of rubber, laminated fabric leather or in fact, any suitable material. However, rubber is found to be the most advantageous material for this purpose. The rubber ring 32 in reality, is a piston .ring, and has an internal, annular'recess 33. Through the walls of the piston as shown in Figure 3 are formed a pair of ports 34 and 35respectively, which ports communicate with an annular recess 36 on the interior of the piston, which recess communicates with a plurality of ports 37, which in turn, communicate with the bore 17 hereinbefore mentioned.

The operation of this preferred embodiment of my invention will now be described. Steam, admitted from the steam chamber in the pump assembly 6, or the main steam line enters the steam end of the motor 4 and develops a pressure within the motor, which pressure is transmitted through the connecting rod 21 to' the smaller piston 23 in the grease gun 5. The grease within the grease gun 5 is thus forced through the alemite connection 26 with an increased pressure, through the bore 14, through the ports 34, 35 and 37 tothe annular recess 33 in the flexible piston ring 32. The piston ring is thus expanded and prevents leakage within the pump. The actual motion of the piston 13 is determined in the usual manner by the action of the piston within the steam-pump 6.

The foregoing description is directed pri marily towards one embodiment of my invention, but as stated before, my invention is susceptible to modification, and a slightly modified form of this invention is disclosed in the second sheet of drawings forming a part of this specification, and more particularly in Figures 4 to 7 inclusive. In this particular case, the port 11 mentioned in an earlier part of this specification, is utilized. A connection between this port and a single grease gun 4 having a piston 19' therein and cup leathers 20 and 20 leads to the power end of the pump 3. The grease end is designated at 22' and the alemite connection 26,

ence between this construction and the pre-' ferred embodiment, resides in the use of slush power instead of steam power to expand the piston 13, and in this particular instance the pressure is merely equalized within the piston and without as the flush power is transmitted through the prescribed course from without the piston to within the piston; while in the preferred embodiment of the invention, steam power is utilized and conse uently, the pressure within the piston may e increased considerably in comparison to the pressure from without the piston. The use of the flexible connections 26 in the first described embodiment, and 26 in the alternative construction, permits the piston rods and the cross-head to travel in their respective courses without interfering with the operation of the auxiliary motor and grease gun. Other parts of my device are merely conventional in form, and no claim is laid as to the novelty thereof.

From the foregoing, it is thought that the construction, use and many advantages of the herein-described combination flush-pump will be readily apparent without further description, and it will also be understood that changes in the form, proportion and minor details of construction may be resorted to without departing from the spirit of the invention or sacrificing any of the advantages thereof.

It will be understood that various changes in the detail of construction may be made without departing from the spirit or scope of the invention as defined by the appended claims.

I claim:

1. A slush pump comprising in combination a cylinder, a piston within said cylinder, a connecting-rod extending through said piston, an annular groove on said piston, a packing of flexible material disposed within said groove, said connecting-rod having a bore therethrough and means communicating with said bore and the internal, annular area of said packing, said means including a cylinder, a piston therein, and a conduit leading from the cylinder of the slush pump to said second named cylinder. whereby fluid pres sure may be applied to said area to expand said packing.

2. The combination of a cylinder, an expansible piston in said cylinder, means for driving said piston, a second cylinder having fluid disposed therein, a piston in said second cylinder and means for driving said second piston, and a passage-way between said second cylinder and said expansible piston whereby said fluid may be forced into said first named piston to expand the same.

3. A slush pump comprising a cylinder having an expansible piston therein, a'second cylinder having a piston therein, means for applying slush power from said first mentioned cylinder to the piston within the second cylinder, and means for transmitting pressure from said second cylinder to the in- Y terior of said expansible piston, whereby the pressure within said piston and around said piston will be equalized.

4. A slush pump comprising a cylinder having an expansible piston therein, a second cylinder having a piston therein, means for applying steam to said second cylinder and 'plston, a connecting rod connecting said pistons, said connecting rod being hollow throughout a portion of its length, a third cylinder having a piston therein, a passageway between said third cylinder and said first cylinder to admit slush pressure from said first cylinder to operate the third piston, a fluid disposed within said third cylinder, and a connection between said third cylinder and said partially hollow connecting rod, whereby fluid pressure may be forced through said connecting rod to the interior of said expansible piston to equalize the pressure within and 5 without the same.

5. The combination of a cylinder, a piston therein, said piston having an annular groove, a rubber packing in said groove, the inner surface of said packing being convex and providing a chamber within said piston,

a hollow connecting rod operating said piston and communicating wlth said chamber, and means lncluding a conduit leading from said cylinder for forcing a fluid through said hol- 5 low piston rod to said chamber to expand said packing.

6. The combination of a cylinder, a piston therein, means for operating said piston, said piston having an annular groove, an expansible packing therein, there being a chamber between the inner surface of said packing and the bottom of said groove, a hollow connecting, rod operating said piston and cominunicating with said chamber, a stationary cylinder connected to said hollow piston rod,

a piston in said last named cylinder for forcing a fluid through said hollow piston rod to expand said packing and means actuated by said operating means to operate said second 00 piston.

In testimony whereof I have signed my name to this specification.

- ANDY MoLEAN. 

